An apparatus of this type is known from WO 2008/025 555 A1. With this known apparatus, it is possible, with high stock removal rate and large removal surface, to mine rock or other hard materials economically, wherein the mill cutting or stock removal takes place radially outside the periphery of the tool drum. The known apparatus can advantageously be used to drive galleries or tunnels with the aid of part-face heading machines provided with an arm which is pivotable transversely to the main direction of advance and on the front end of which the tool drum is rotatably mounted.
It has been shown, however, that precisely in such applications, the efficiency of the apparatus with its tool carriers, which in the milling operation all rotate in the same direction, is still open to improvement. The rotational direction which is the same for all tool carriers has a detrimental impact, in particular, when the machine extension arm, which carries the tool drum, is pivoted to and fro, in that namely the milling performance in one pivoting direction of the machine extension arm is better than in the other pivoting direction.
The invention has set out to avoid these drawbacks observed in connection with the known apparatus and to improve an apparatus for the milling cutting of rock or the like, of the type stated in the introduction, such that, irrespective of the motional direction of the tool drum, an equally good milling performance of the cutting tools mounted on the tool carriers is achieved.